The reliability and performance of digital information appliances, in particular portable ("laptop" or "notebook") computers, are closely related to the temperature at which the device's internal electrical and electronic components operate. For example, a typical portable computer includes a number of internal electrical and electronic components mounted on one or more circuit boards supported within the computer's housing. During periods of heavy use, these components may generate excess heat that must be dissipated outside of the appliance to prevent damage to the computer or degradation of its performance. However, the desirability of providing compact size in portable computers necessitates the consideration of alternate cooling methods typically not utilized in "desktop" computer systems due to limited space within the portable computer's housing for adequate cooling apparatus (heat sinks, cooling fans, and the like).
The problem of providing sufficient cooling to portable digital information appliances is greatly magnified by the increasing use of higher-powered components that generate greater amounts of heat. For instance, as portable computers have evolved, they have continually employed faster and more powerful processors that consume increasing amounts of power from the computer's battery during operation. As a result, the speed of processors utilized by portable computers has been somewhat limited by the necessity of providing adequate battery life for portable operation. Faster processors also generate more heat than their slower predecessors further limiting their use. In addition, faster processors also make other devices in the portable computer fun faster, generating even more heat, contributing to further increases in temperature.
One method of overcoming these shortcomings and improving the maximum performance of processors utilized in portable computers is to reduce the speed of the processor while the computer is powered by its battery. When external power is provided the processor is allowed to operate at a higher speed. However, when the processor is operated at the higher speed, it typically produces a greater amount of heat thus necessitating the use of larger cooling apparatus such as heat sinks, cooling fans and the like, than would be required while the processor operates at the slower speed. The use of larger cooling apparatus increases the portable computer's size and weight, and in the case of cooling fans, when operated without external power, consumes additional power that unnecessarily reduces its battery life. Consequently, it becomes desirable to provide supplemental cooling to the digital information appliance while operating on external power (i.e., while its processor is operating at a higher speed).
For this purpose, external docking stations have been developed that include cooling apparatus for providing supplemental cooling to the portable computer while docked therein. However, such docking stations are optional and not always purchased with every portable computer. Further, docking stations, like "desktop computers" are stationary, and thus cannot provide supplemental cooling when the portable computer is operated portably (e.g., operated at remote locations using external power so that operation of the processor at the higher speed is desirable). Further, larger cooling apparatus, such as cooling fans or the like, contained within the portable computer or docking station often produce excessive noise during operation which may become distracting to the user. Finally, docking stations, while often employed with portable computers, may not be suitable for use with other types of digital information appliances.
As a result, it is desirable to provide apparatus capable of furnishing supplemental cooling to a digital information appliance capable of being operated portably at remote locations. Such an apparatus may further be physically separated from the digital information appliance so that any noise it generates is less perceptible to the user.